The introduction of exogenous molecules into cells plays a significant role in recombinant technology, therapeutic applications, genetic analysis, cell tracking or cell trafficking. For example, delivery of genetic materials into cells is a key technique in recombinant DNA technology and has immense importance in genetic analysis. In transfection, the cells are administered with naked DNA, which are introduced into the cells to produce an RNA and/or protein.
A successful delivery of exogenous molecules into cells in an in vitro system can be achieved by various techniques to improve efficiency of the delivery technique without perturbing the structure or function of the cells. One or more techniques are known in the art to introduce exogenous molecules into the cells which include, but are not limited to, microinjection, liposome based cell fusion, electroporation, and ballistic methods. Moreover, pulse electric field and diagnostic ultrasound are presently used for permeabilization of cells. Among these techniques, electroporation has been used for various types of cell transfection, though it is largely disruptive and causes cellular death.
To increase the efficiency and to minimize the side effects of various methods, optical-based delivery was introduced. For example, laser based microinjection, optoinjection or optoporation are used for gene delivery. Use of lasers for cell transfection is an efficient method, and the hole formed by the laser beam is found to repair itself within a short time span. In optoporation, either permeability of the cell membrane is changed or pore formed at the site of the laser beam contact on the plasma membrane, and these techniques do not damage the cells extensively. In most of the optoporation techniques, the permeability of the cells is modified at the site at which the laser impacts the cell membrane. However, the methods of laser based microinjection, optoinjection or optoporation presently employ high numerical aperture, or expensive light sources (e.g., solid-state lasers) and the methods only allow for low throughput because they are generally focused on single cell transfection.
Therefore, optical based delivery techniques which are inexpensive and provide high throughput molecular delivery into cells with high transfection efficiency are desirable.